Granted Patent
Utility
US 4,356,084 · App. 06/027,577
Self-sealing valve assembly to facilitate unplugging of a centrifugal cleaner
Inventors:
Derald R. Hatton, David E. Chupka
Patented Case
View Patent ↗
Granted: Oct 26, 1982
Filed: Apr 6, 1979
Inventors
Derald R. Hatton
David E. Chupka
Assignee (at issue)
Black Clawson Company, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.